# Questions tagged [electron]

Anything related to the behavior and properties of electrons, i.e. the elementary subatomic particles accounting for electrical conduction in most solid materials, especially metals.

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### Why does electric current not disobey Heisenberg's uncertainty principle?

So, the definition of current, or the magnitude of current, that I have found is that it's the rate at which the electrons flow through a cross-section of a wire. But that means knowing exactly where ...
83 views

### Shot noise converted to digital value

I'm trying to estimate the standard deviation in the final digital value that originates from shot noise only, when using a standard smartphone camera. In high illumination, shot noise is supposed to ...
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28 views

### Can a photon be modeled using AC driven electron and AC driven wire loop?

Can a photon ("electromagnetic wave packet") be simulated in software as an electron bouncing up and down (for the oscillating E field) and a loop of electrons with neutralized electrostatic ...
• 103
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### Carrier concentrations versus temperature and doping in Matlab

I am currently self studying structure of semi-conductors and I would like to make a graph in Matlab of the number of carriers as a function of temperature and doping. Let's say that I am testing ...
229 views

### Deflection of current in a metal plate conductor

If I have a metal plate (square in shape) and an electric current moves from one side to the other. I understand that most of the current will take the path of least resistance but all paths will be ...
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1 vote
35 views

### How to calculate the diffusion length in modulation doping?

I have read a paper about an application of modulation doping in bulk thermoelectric materials. In this paper, the nanoparticles diffuse carriers into the host materials, and I want to estimate the ...
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130 views

### Why do electrons move in a circuit? [closed]

I am trying to make sense of why electrons move in a circuit. I did my research and the first answer I got is because of the difference of electric potential between the two points of the battery that ...
1 vote
157 views

### Current in BJT at EBJ and its mechanism about Diffusion and Drift Current

I have seen this post and I'm still confused about what mechanism would be applied on majority carrier, and it seems to me that the post I cite only explain about how the minority carrier move from ...
• 111
64 views

### How I can use light to control of amplifier?

I want to make a car that I can control by light, and I thought of using a photoresistor and a light sensor to control the amplifier to make it perform two functions. The first function is to make the ...
1k views

### Is it possible to make cathode ray or electron gun without a vacuum?

I stumbled upon this picture on the internet here is the link https://www.reddit.com/r/ElectroBOOM/comments/16azeq5/cathode_ray_succesfully_shooting_a_plasma_beam_in/ I wasn't able to get info from ...
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160 views

### Propagation speed and capacitors charging speed of transmission line

I am a bit confused on the speed of voltage propagation in the transmission line and I hope someone can enlighten me. I understand the speed of step up voltage propagation is in the same order as the ...
1 vote
432 views

### Why does the neon screwdriver (phase meter) light on just by touching the phase wire?

I had a question, can you answer it: as you can see in the picture I uploaded, the single-phase alternating current flows in one wire at one moment and in the next moment from another wire as in the ...
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### Two power sources

Please consider a circuit with two loops where the two loops have a common part with a single resistor. There are two power supplies (or of it matters say these are voltage sources, like batteries, ...
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124 views

### Is there a colour code for electron flow notation? [closed]

I'm building a power supply for electro-chemistry experiments. It would make more sense to have the output correctly denote which terminal is 'electro-negative' and which is 'electro-positive' instead ...
1 vote
177 views

### Moving electrons on the surface of a thin metal sheet with high current

I don't know if this is the right place to ask this because my question is a mix of physics and electronics. I'm in 12 grade, and wish to conduct a simple physics experiment. I would like to observe ...
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173 views

### Trying to understand electron flow in a rapid start ballast fluorescent light system

While looking into what is required to upgrade a fluorescent tube light to a LED solution, I found that I don't truly understand what is happening with existing fluorescent solutions. I understand the ...
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1 vote
148 views

### Effective Mass of Electrons

In electronics, the fact that mobility of electrons is higher than the mobility of holes is frequently used. How can we explain this using effective mass of electrons and holes ?
1 vote
278 views

### What is the total charge Q of 1 m³ of copper?

I was wondering if I can calculate the total charge Q of 1 m3 of copper, see my calculation in the picture below. Is this correct? The correct solution (thanks to the community in the comments below):...
44 views

### Reasoning behind the density of free electrons/holes being constant with respect to volume of a semiconductor material

Consider a silicon semiconductor material which is having a cuboid shape of dimensions $2\times 2\times 1\ \mathrm{cc}$, suppose the atomic density of silicon is $10^{22}/\mathrm{cc}$, so in all ...
395 views

### How do receiver circuits differentiate between carrier/signal waves?

I've been told and shown that a receiving antenna will pretty much pick up any signals around itself. You can then filter out the frequency you want in order to do something with it. What I don't ...
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853 views

### Can electron microscopes record video of electricity?

Since electron microscopes capture electrons, can they be used to capture electrons moving in a circuit, and have they been used for this?
133 views

### Conventional current and electron flow in Arduino

On an Arduino there are some pins named GND, some are 5 V, and so on. If electrons flow from the negative to the positive terminal, then does this mean that they are flowing from GND to one of the ...
148 views

### Fermi level of metal

Do metals have fermi level? As we know conduction band and valence band are overlaped for a metal. Does it make any sense for metals to have fermi level?
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### Can very small currents be accurately measured using only standard analog electronic components on an IC? [closed]

Let's say, for example, that I have a photodiode, which produces electrons in response to the amount of light. What is the theoretical lower limit that can be accurately measured only using basic ...
136 views

### Is it possible to force charges into one plate of a capacitor?

As we know, a capacitor stores energy, but the net amount of charge in it doesn't change. If an electron enters one plate, another leaves the other plate. If the other plate is floating, the entering ...
2k views

### Why don't most electrons hit the anode in a cathode ray tube or electron gun?

In a cathode ray tube or electron gun, electrons liberated from the cathode by thermal emission accelerate towards a ring-shaped anode, from the potential difference between cathode and anode. If an ...
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4k views

### Do electrons flow from higher to lower or lower to higher potential?

I have seen countless sites saying electrons flow from higher potential to lower potential, but then again I have seen many saying that electrons flow from lower potential to higher. I have always ...
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224 views

### Are vehicle electrical components powered from the negative side?

still trying to get my head around electron flow as opposed to conventional current regarding automotive electrical circuits. There seems to be a ton of conflicting information/advice out there so I'm ...
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2k views

### How is current the derivative of charge

If electric current is the time rate of CHANGE of charge. Then if I have a DC fixed current flowing into a resistor, same amount of charge is always flowing to that resistor, hence the derivative of ...
4k views

### The probability that an electron occupies the fermi level at 0K

I was trying to find the probability that an electron occupies the Fermi level at 0K. Fermi function: {exp[(E-Ef)/kT] + 1}-1; (k = 8.314 J/mol/K) According to my calculations, the answer would be 0.5. ...
214 views

### 3 Phase Motor to DC Output

In a standard car alternator there is are 3 diodes that keep each of the phases from ever pulling electrons. There is then a capacitor to smoothens it all out. However how is it possible that the ...
89 views

### KCL when rate of electron flow is given ; To include electron sign or not

Q) We have to determine the I. Magnitude of electron charge is 1.6 x 10^-19C. I have fundamental confusion in this problem. Should we consider the negative charge of electron while doing the problem. ...
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1 vote
60 views

### Generation of electrostatic induction

I need to generate a 500 volt electrostatic charge. How can I do this? I don't have a Van de Graaff generator. What are some practical suggestions? Basically I want to do an experiment in which I need ...
29 views

### Repelling charges and current flow

The electrostatic force between two like charges is repelling. This concept is fairly clear to me with Coulomb's law and electric fields. So two electrons will repel each other. Given this statement, ...
660 views

### Why are low band gap semiconductors (like silicon) not ideal for most solar cells? Are their atoms ionized by higher-energy photons?

Most sources on the web say that 1.3 eV or 1.4 eV is 'ideal' for most solar cells... What happens to lower-gap, gapless or overlap materials (conductors)? Are they ionized, rather than sending their ...
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1k views

### Why is there EMF present when there is no current?

Current means the rate of flow of charge. Electrons are the ones that carry charge in current. From the definition of EMF (electromotive force), When no current is drawn from cell, the potential ...
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661 views

### What does charge on an electron mean?

As I have read , charge is electrons , protons or neutrons. Now , according to definition of current , current is the rate of flow of charge I.e flow of electrons. Then , I=Q/t . Unit of Q is coulomb &...
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1 vote
114 views

### Majority Charge carriers and electron holes

Suppose I have an extrinsic semiconductor made of silicon and doped with phosphorous. Now, phosphorous has one more electron than silicon. After replacing one silicon atom, and taking its place, the ...
248 views

### Shelly 1 Configuration

I am trying to implement the Shelly 1 switch for an electronic device I have. The electronic device has an open collector output channel (AUX1). It also has two output pins Z8 and C. When Z8 and C are ...
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### Can current flow from positive to positive in real life

How to implement a circuit diagram where there are 2 batteries and negative to negative have load and postive to positive have some load. How to implement, like build in real life this ...
3k views

### Is there a mnemonic to remember direction of current flow?

I have always stumbled when remembering which current flow notation to use. In my mind, it's by default conventional current flow. But, I also have in mind electron flow notation. Do you know of a ...
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### How many newtons are there in one coulomb of charge?

Or, I should have said, how many newtons of force does one coulomb of charge exert? At a distance, presumably, of one meter? Since N/C is supposedly equivalent to V/m? P.S. What are the values for a ...
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100 views

### Removing collected charges in a IC CMOS circuit exposed under a 30keV electron beam source

I would like to know if there is any mechanism (for example UV light exposition) to remove charges collected in an IC CMOS circuit that was exposed under a 30keV electron beam source. Presumably, ...
657 views

### Can a floating capacitor terminal be used to collect electrons?

I want to collect charge from an electron beam source. For that, I'm proposing to put a floating capacitor with its bottom terminal floating and directly exposed to the electron beam gun. The top ...
1 vote
193 views

### Why does current continue flowing in a circuit?

Sorry for the amateur question, but I'm having trouble understanding this phenomenon. In a closed circuit, electron current flows from the negative terminal of a battery to the positive terminal. But ...
179 views

### Signal interference in receiving antenna?

I’ve been scouring the interweebs for some insight into how electrical signals travel in a wire. More specifically, I cannot wrap my head around how a receiving antenna works with hundreds if not ...
6k views

### In which direction do electric signals flow?

We know that electrons move from the negative to positive terminal, and that holes flow in the conventional direction of current - from the positive to negative terminal. I've always assumed that this ...
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902 views

### Electrons flow in Li-ion Battery

I’m new to electricity, and I’ve got a question about electrons flow inside a Li-on battery. A lot of articles and videos show us only Li+ ion flows from anode to cathode through electrolyte during ...